Icon for a display screen



FIG. 1 is a front view of an icon for a display screen, the broken line outlines of the display screen are for illustrative purposes only and form no part of the claimed design, the dotted lines in the central part of the icon are part of the claimed design; and,

FIG. 2 is a front view of a second embodiment thereof, the broken line outlines of the display screen are for illustrative purposes only and form no part of the claimed design, the dotted lines in the central part of the icon are part of the claimed design. 

The ornamental design for an icon for a display screen, as shown and described. 